If you're like many Chrome users, you have a habit of leaving tabs open on the app. For those who are forgetful, Google is testing a feature that will remind users every now and then to clear their tabs. The reminder, spotted by 9to5 Google, was first listed in a commit log back in August that mentioned a way "to assist the user in closing stale/unused tabs." To get the reminder working with the Chrome browser on your Android phone, you will need to enable a flag and we will give you the directions in a second.
If you don't want to add another browser (especially an unstable one) to your device, you can still receive the reminders. Open the Chrome browser and enter chrome://flags. In the search box that appears at the top of the page, type in #enable-close-tab-suggestions. Enable this flag, relaunch the browser, and you're all set. Whenever some of your tabs get "stale," you will get a reminder that says, "X of your tabs haven't been used lately. Close them?" You can dismiss the alert or review the open tabs. If you review the open tabs, you will get the opportunity to select the ones that you want to be closed.
It's just another example of Google trying to make life easier for Android users.